In accordance with a rapid spread of information relevant apparatuses and communication apparatuses such as a personal computer, a video camera and a portable telephone in recent years, the development of a battery to be utilized as a power source thereof has been emphasized. The development of a high-output and high-capacity battery for an electric automobile or a hybrid automobile has been advanced also in the automobile industry. A lithium battery has presently drawn attention from the viewpoint of a high energy density among various kinds of batteries.
Liquid electrolyte containing a flammable organic solvent is used for a presently commercialized lithium battery, so that the installation of a safety device for restraining temperature rise during a short circuit and the device for preventing the short circuit are necessary therefor. On the contrary, with a lithium battery, namely a battery all-solidified by replacing the liquid electrolyte with a solid electrolyte layer, the simplification of the safety device may be achieved since the flammable organic solvent is not used in the battery. A sulfide solid electrolyte material has been known as the solid electrolyte material to be used for an all solid lithium battery. For example, Li2S—SiS2—Al2S3 is exemplified as a sulfide solid electrolyte material in Claim 4 of Patent Literature 1.